However, the Asian countries stopped short of backing Russia's move to recognize the independence of the breakaway province, along with Georgia's other rebel region, Abkhazia.
"The leaders of the SCO member states welcome the signing in Moscow of the six principles for regulating the South Ossetia conflict, and support Russia's active role in assisting peace and cooperation in this region," a joint declaration adopted at the SCO summit in Tajikistan said.
The security bloc, seen as a counterweight to NATO's influence in Eurasia, comprises China, Russia, and four Central Asian states - Kazakhstan, Kyrgyzstan, Tajikistan, and Uzbekistan.
Western powers have warned Russia that it faces "international isolation" over its continued security presence in Georgia, three weeks on from Tbilisi's attack on South Ossetia, and over its recognition of the two provinces.
The six leaders called for peaceful dialogue to resolve ongoing tensions.
"The SCO member states are deeply concerned over tensions around the South Ossetian issue, and call on all sides concerned to peacefully resolve existing problems through dialogue," the declaration said.
The meeting of the regional bloc comes a day after the foreign ministers of Canada, France, Germany, Italy, Japan, the United States and Britain adopted a statement condemning Russia's peacekeeping presence in Georgia and its recognition of the rebel regions.
President Dmitry Medvedev said recognition was necessary to protect the republics from Georgian acts of aggression, following the August 8 military offensive in South Ossetia.
Medvedev had urged the leaders at the summit in the Tajik capital, Dushanbe, to support Russia's role in Georgia, in order to "send a serious signal to those who are trying to justify the aggression that was committed."
He also criticized the role of Western powers in the conflict.
"It is well known who connived with the Georgian authorities and even goaded them on, in pursuit of their own selfish goals. In these extreme conditions, we stayed calm and continued a responsible and predictable line of policy," he said.
The Russian leader, whose country will now take over the presidency of the SCO from Tajikistan, said that the recent conflict has increased the importance of the bloc as a guarantor of regional security and stability.
"The importance of this task has now grown. To achieve it, we must avoid confrontational thinking, while strictly keeping to the principles of international law."
Medvedev met earlier in the day with Kazakh President Nursultan Nazarbayev for one-on-one talks.
Nazarbayev voiced his country's support for Russia's operation to force Georgia to peace, and condemned Georgia's attack on the South Ossetian capital.
"The West has ignored the attack by the Georgian military on Tskhinvali. I believe that is how it all started," he told Medvedev.
"We all believe that the subsequent actions by Russia were aimed at protecting this long-suffering people," Nazarbayev said.
At the SCO summit's final meeting, Medvedev announced that next summit will be held in the second half of June 2009, in the Russian Urals city of Yekaterinburg.
